Magnetic lock relay



1948- G. L. BUSH I 2,447,632

meunnc LOCK RELAY Filed June 1, 1946 FIG; I

i O u n g F G. 4 a: O

TIME IN SECONDS INVENTOR G. L. BUSH 46 BY M ATTORNEY Patented Aug. 24, i948 MAGNETIC LOCK RELAY George L. Bush, Flushing, N. Y., assignor to The Teleregister Corporation, New York, N. Y., a

corporation of Delaware Application June 1, 1946, Serial No. 673,873

6 Claims.

1 This invention relates to magnetic lock relays, and more particularly to an improved relay of this character. which is adapted to store electrical signals without requiring holding current or other drain on the power supply while the signals are stored.

In various types ,0! systems in which locking relays are employed .for electrically storing information in regard to a number of items in communication and posting systems, for example, airway trailic control systems, thousands of such relays may be required in a single installation. If the mechanical' locking type of storage relay is employed, this not only results in an undesirably expensive unit, but the size of the unit is such that unduly large space requirements have to be provided for the large number of relays employed, and in-locat'ions where such equipment is employed space usually is at a premium. If storage relays are employed which have locking windings, these also are unduly expensive and often require more room than is available for the number of relays required. Moreover, there is a considerable drain on the current supply in order to maintain the locking windings of a large number of these relays energized continually, and even more serious is the fact that in the event of a temporary failure of the power supply, the information stored is lost and sometimes is of a nature which cannot again be obtained.

One of the objects of the invention is a compact magnetic lock relay which avoids the ioregoing disadvantages, and which retains the stored information irrespective of any interruption in the power supply.

A further object is a magnetic lock relay oi the character described which requires only low operating current and low releasing current, and

which except for. the intervals of operating or releasing the relay, requires no current consumption.

A further object is a magnetic lock relay which is so constructed as to be adapted to quantity production methods and thus may be produced at a relatively low cost.

Still another object is a magnetic lock relay which may readily be removed or replaced for inspection, maintenance or repair purposes, without disturbing existing electrical connections.

Other objects and advantages of the invention will be apparent from the following detailed description, taken in connection with the accompanying drawings in which- Fig. 1 is a top plan view of a magnetic lock relay embodying the principles of the invention;

- Fig. 2 is a side view, in elevation, of the relay;

Fig. 3 is an end view, in elevation, of the front .of the relay;

Fig. 4 is a graph showing certain operating characteristics of the relay; and

Fig. 5 illustrates a simplified control circuit for operating and releasing the relay.

Referring to Figs. 1 to 3 of the drawings, the relay comprises a supporting body of a phenolic condensation product or other suitable insulating material, which preferably is assembled from three pieces 8, l and B to facilitate quantity production methods during manufacture, which body serves as a support for the elements of the relay. The members 6, l and indirectly the member 8, along with other elements of the assembly, are firmly clamped together by machine screws 9 which pass through an armature back stop l0 and are screw-threaded into a magnetic yoke 26. A nonconductive strip 53 insulates the member ill from the electrical elements of the unit.

The signals are stored on the relay by means of sets of complementary contact springs it and i5, three sets of these contacts being shown in Figs. 1 and 3 of the drawings for storing three signals representing items of information, although as many sets of contact springs may be provided as are desirable in view of the nature of the information stored. In the drawings the contact springs are shown in closed circuit position. Preferably, they are of the twin contact type in which each of the relatively stationary springs it has two contact points l5 which are engaged by a complementary contact plate Ml on the movable spring it, so that there is little likelihood of dust or other foreign substances preventing good contact between at least at one of the pairs of complementary contacts. Each of the movable contact members Ml comprises a continuation of a strip 56, preferably of nickelsilver, which extends along the top to the rear or left-hand end of the unit as viewed in Figs. 1 and 2, and the flat surface portions of these strips provide electrical slip connections for the movable contacts M of the unit. Also, the spring strips 16 collectively serve as the armature spring of the unit, the armature 18 comprising a strip of magnetic iron which is secured, as by machine screws Hi, to a pile-up and insulated from the spring strips l6 by means of an insulation strip 20. Above the strips 56 are two insulation strips 20 and 2!, and on top of the pile-up is an iron plate 22, preferably of magnetic iron through which the machine screws pass, these being screw-threaded into the armature l8 to clamp I the pile-up together. The bottom plate member I l is also secured by machine screws 25 which pass through the strip 8 of insulation, and are screw-threaded into a plate 28 of iron which forms a magnetic yoke for the magnets hereinaiter described. The fixed contact springs 15 each comprises a continuation of a nickel-silver strip H which extends along the bottom of the unit to the rear thereof, and which like the top strip members l6 provide electrical slip connections for the stationary'contacts oi the ,unit. A

nonconductive strip 21 insulates the plate ll from the strip H. The strips I! have apertured portions, such as shown in Fig. 2, to provide clearance for the machine screws 9 and 25 and insulate'the strips from the screws, and this is likewise the case with the upper strips l through which the screws 9 pass.

Secured to the yoke member 26, by magnetic attraction, is a small cylindrical permanent magnet 30; the magnet preferably is composed of a magnetic alloy characterized in that it has a high residual magnetism, so that when an electromagnetic field is set up in the magnet it retains permanently a considerable portion of the flux induced therein. Various such alloys suitable for the purpose are well known, for example, a sintered nickel-ironraluminum alloy commonly known in the trade as Alnico No. 5. Surroundmg the lower end of the permanent magnet is an insulation strip 32 which has an apertured portion therein that surrounds and closely fits the lower end oi the permanent magnet thereby preventing the magnet from sliding out of position, and an upper insulation strip 33 is provided for positioning the upper end or pole of the permanent magnet 30. These strips also provide, in efiect,spool ends for an electromagnet 35, the coil having an inner core 36 of'magnetizable material such as iron which is secured to the yoke member 25 either by a screw or by riveting. The connections to the operating coil 55 preferably are made by means of nickel-silver strips 5'5, 38 respectively secured to the opposite sides of the body member 5, these strips serving as slip connections for making contact to the operating coil. The front end of plate member ii .is provided with a turned-up edge portion 55 whereby the unit readily may be removed from its supporting mounting or socket either by the fingers or by a tool.

The resiliency of the spring strip members is is such that when the armature i8 is in its uppernicst position, against the back stop it, the re- 4 remains sufliciently strong to hold the armature in circuit-closing position and thus electrically store the signals transmitted to the unit. The armature preferably has a small spacer 42, Fig. 2, of nickel-silver or other suitable nonmagnetic material, is secured thereto as by brazing or soldering, thereby to maintain a small airgap between the armature and the end of magnet and prevent sticking oi the armature when it is-to be released.

Whenever it becomes necessary or desirable to release the information stored in the unit or to change it, a small releasing current having a p0- larity opposite that or the energizing current, momentarily is passed through the winding 35, and this opposes the flux maintained by the permanent magnet and reducesthe residual mag-' ance of the coil may be of the order of 375 i0 preferably is made of magnetic iron, and iron machine screws 9 are used; since the screws pass through and engage the yoke member 26, the back stop has some magnetic attraction for the plate 22 and the screws l5, so that it aids in retaining the armature in open-circuit position. When a small operating current is passed through the magnet coil 35, however, this increases the magnetic field about the upper pole of the magnet 30 so that it attracts the armature and closes the several sets ohms, and the coil is preferably composed of approximately 1700 turns of No. 40 magnet wire. A resistance 45 which may be of the order of 1500 ohms in the circuit. illustrated, is provided in order that a suitable operating source of potential 46, for example, 50 volts, may be employed. When the switch 41 momentarily is thrown to its right-hand position, as viewed in the figure, current will flow in a direction through the coil 35 to aid the flux of the permanent magnet 30 and thus attract the armature which, as above set forth, remains operated by the residual magnetism until a releasing current subsequently is passed through the coil. When it is desired to clear out the signals stored on the relay contacts, the switch member 41 momentarily is thrown to the left, as viewed in the figure, and this reverses the flow of current through the coil 35, thereby causing the magnetic flux set up by the coil to oppose the residual magnetism of the permanent magnet and release the armature. While a manually operable switch circuit is shown for the sake of simplicity, in practice the unit is operated and released automatically, as by means of cam-controlled contacts, relays or the like. In a unit having the values above set forth, an operating current as low as 27 milliamperes produces satisfactory operation of the relay, and a current of like value causes release of the relay.

It will, therefore, be seen that many thousands of the relay units may be employed in a single installation without requiring an excessive strain on the power supply, it being understood that all of the relays are not actuated or released at the same time, since the information regarding dif- I curve 5| .the release characteristics under this condition. Curve 54 shows the operate characteristics when the resistance 45 is included, and curve 55 the release characteristics in this case. The curves 54 and '55 show that a voltage drop of stamped mechanical parts, with the exception of the electromagnet 35, and thus the unit is especially adapted for quantity production, with consequent lowered cost. Only a very small number ary contact structure complementary to said movable contact structure. a magnetic yoke secured I to said body and a permanent magnet extending from said yoke and operative upon said armature, the permanent magnet being formed from a magnetic material characterized by high residual magnetism, the spring tension of the movable contact p i g strip being sufllcient to prevent the residual magnetism in said magnet from operating the arof different parts are required for the uni-t, and

all of the operating parts including the electrical connections are readily availablefor inspection, maintenance or repair purposes. For storing signals of the character employed in airway trafllc and similar posting system, the unit may be made so small that its overall length is only approximately 2% inches; its overall width is of the order of /2 inch; and the overall eight of the unit including the contact springs is less than 1 inch, so that thousands of these units may be inserted adjacent to each other in a relay bank, in a manner to conserve valuable space. Preferably, and as shown in Fig. 2, the right-hand end of the strip 35 extends sufficiently to provide a suitable stop for the follow-up movement of the stationary contact springs l5 when the contacts are opened.

The nickel-silver strips are prevented from laterally shifting by means of small dimples or burrs 48, 48' which are punched into the strips and caused to extend for a slight distanceinto the supporting insulation body members. The strips 16,

11, 31 and 38 not only serve as electrical slip connections for engagement with fixed spring contact members in the relay bank, but also mechanically secure the relay unit in operating position and firmly support the unit on all four sides thereof. The unit thus may be withdrawn readily from the relay bank for inspection, maintenance or repair purposes, and either the same or another unit may as readily be reinserted in the bank.

It will be noted from Fig. 4 that the time required for operating and releasing the relay armature is materially lessened when the resistance 45 is employed. This is because theresistance causes a faster build-up of the current in the coil 35, and hence the flux induced therein, and thus improves both the operate and release characteristics of the unit.

Various modifications of the relay unit illus-' trated will readily occur to those versedin the art without departing from the spirit or scope of the present invention. The disclosure, therefore, is for the purpose of illustrating the principles of the invention, which is not to be regarded as limited except as indicated by the scope of the appended claims.

What is claimed is:

1. A magnetic lock relay comprising a'supportin body of insulation, at least one spring strip mature when it is in its released position, but insufilcient to cause release of the armature when it has been attracted to said permanent magnet, an

electromagnet having a core extending from said yoke and so positioned that when an operating current is passed through the ,electromagnet in one direction flux is set up to aid the permanent magnet and operate the armature and when current is passed in the opposite direction through the electromagnet flux is set up which opposes the residual magnetism of the permanent magnet and releases the armature, the residual magnetism of the permanent magnet maintaining the armature in its operated position upon deenergization of said. electromagnet.

2. A magnetic lock relay comprising a supporting body of insulation, at least one spring strip conductor secured to and extending longitudinal- 1y along a side of said body, an armature secured to said strip whereby the strip provides spring supporting and biasing means for the armature, electrical contact structure on one end of said strip and movable by said armature, at least one other spring strip conductor secured to and extending longitudinally along a side of said body and having on one end thereof relatively stationconductor secured. to and extending longitudinally along a side of said body, an armature secured to said strip whereby the strip provides.

spring supporting and biasing -means for the armature, electrical contact structure on one end of said strip and movable by said armature, at least one other spring strip conductor secured to and extending longitudinally along a side of said body and having on one end thereof relatively stationary contact structure complementary to said movable contact structure, a magnetic yoke secured to said body and a permanent magnet extending from said yoke and operative upon said armature, the permanent magnet being formed from a magnetic material characterized by high residual magnetism, the spring tension of the movable contact spring strip being sufficient to prevent the residual magnetism in said magnet from operating the armature when it is in its released position, but insufficient to cause release of the armature when it has been attracted to said permanent magnet, an electromagnet having a core extending from said yoke and so positioned that when an operating current is passed through the electromagnet in one direction flux is set up to aid the permanent magnet and operate the armature and when current is passed in the opposite direction through the electromagnet flux is set up which opposes the residual magnetism of the permanent magnet and releases the armature, the residual magnetism of the permanent magnet maintaining the armature in its operated position upon deener-' gization of said electromagnet, the longitudinally extending portions of said spring strip conductors providing slip connections for the relay whereby its said contact structures readily may be connected to or disconnected from complementary external connections.

3. A magnetic lock relay comprising a supporting body of insulation, a plurality of spring strip conductors secured to and extending longitudinally along one side of said body, an armature secured to said strips whereby the strips collectively 'provide spring supporting and biasing means for the armature, electrical contacts on the ends of said strips and movable by said armature, a plurality of other spring strip conductors secured to and extending longitudinally along another side of said body and having on the ends thereof relatively stationary contacts complementary to-said movable contacts, a magnetic yoke secured to said body and a permanent magnet extending from said yoke and operative upon said armature, the permanent magnet being formed from a magnetic material characterized by high residual magnetism, the spring tension of the movable contact spring strips being sufllcient to prevent the residual magnetism in said magnet from operating the armature when it is in its released position, but insufficient to cause release of the armature when it has been attracted to said permanent magnet, an electromagnet having a core extending from said yoke and so positioned that when an operating current is passed through the electromagnet in one direction flux is set up to aid the permanent magnet and operate the armature and when current is passed in the opposite direction through the electromagnet flux is set up which opposes the residual magnetism of the permanent magnet and releases the armature, the residual magnetism of the permanent magnet maintaining the armature in its operated position upon deenergization of said electromagnet.

4. A magnetic lock relay comprising a supporting body of insulation. a plurality of strip conductors secured to and extending longitudinally along one side of said body, an armature secured to said strip whereby the strips collectively provide spring supporting and biasing means' for the armature, electrical contacts on the ends of said strips and movable by said armature, a plurality of other spring strip conductors secured to and extending longitudinally along another side of said body and having on the ends thereof relatively stationary contacts complementary to said movable contacts, a magnetic yoke secured to said body and a permanent magnet extending from said yoke and positioned between the sets of longitudinally extending strips and operative upon said armature, the permanentmagnet being and positioned between the sets of longitudinally extending strips and adjacent to said permanent -magnet so that when an operating current is passed through the electromagnet in one direction flux is set up to aid the permanent magnet and operate the armature and when current is passed in the opposite direction through the electromagnet flux is set up-which opposes the residual magnetism of the permanent magnet and releases the, armature, the residual magnetism of the permanent magnet maintaining the armature in its operated position upon deenergization of said electromagnet.

5. A magnetic lock relay comprising a supporting body of insulation, at least one spring strip conductor secured to and extending longitudinally along one side of said body, an armature secured to said strip whereby-the strip provides spring supporting and biasing means for the armature. electrical contact structure on one end of said strip and movable by said armature. at least one other spring strip conductor secured to and extending longitudinally along another side release of the armature when it has been attracted to said permanent magnet. an electromagnet having a-core extending from said yoke and so positioned that when an operating current is passed through the electromagnet in one direction flux isset up to aid the permanent magnet and operate the armature and when current is passed in the opposite direction through the electromagnet flux is'set up which opposes the residualmagnetism of the permanent magnet and releases the armature, the residual magnetism of the permanent magnet maintaining the armature in its operated position upon deenerglzation of said electromagnet', a plurality of other strip conductors secured to and extending longitudinally along at least one other side of said body and connected to said electromagnet. the longitudinally extending portions of all or said strip conductors providing slip connections for the relay whereby the relay readily may be connected to or disconnected from complementary external connections.

- 6. A magnetic lock relay comprising a supporting body of insulation, at least one spring strip conductor secured to and extending longitudinally along a first side of said body, an armature secured to said strip whereby the strip comprises spring supporting and biasing means for the armature, electrical contact structure on one end of said strip member and movable by said armature. at least one other spring strip conductor secured to and extending longitudinally along a second side of said body and having on one end thereof relatively stationary contact structure complementary to said movable contact structure, a magnetic yoke secured to said body and a permanent magnet extending from said yoke and operative upon said armature, the permanent magnet being formed from a magnetic material characterized by high residual magnetism. the spring tension of the movabl contact spring strip comprising means to prevent the residual magnetism in said magnet from operating the armature when it is in its released position, but insufficient to cause release of the armature when it has been attracted to said permanent magnet, an electromagnet having a core extending from said yoke and so positioned that'when an operating current is passed through the electromagnet inone direction flux is set up to aid the permanent magnet and operate the armature and when current is passed in the opposite direction through the electromagnet flux is set up which opposes the residual magnetism of the permanent magnet andreleases the armature. the residual macnetis'm of the permanent magnet maintaining the armature in its operated position upon deenergization of said electromagnet. two other strip conductors respectively secured to and extending longitudinally along two other sides 01' said body and connected to said electromagnet, the 101131- tudinally extending portions of all of said strip 2,447,632 9 conductors providing means for connecting the relay to external circuit connections.

file of this patent:

UNITED STATES PATENTS GEORGE H Number Name Date 114,657 Edison May 9, 1871 REFERENCES CITED 306,225 Cummings Oct. 7, 1884 r 686,272 Dunbar Nov. 12, 1901 The following reference are of record in the Romy Man 3, 1904 

